There are literally hundreds of martial arts practiced in Asia and elsewhere in the world, and many of them, including GiCheon, share common elements. What makes GiCheon unique, however, is the principle of YeokGeun, or locking of the joints.
In every position of GiCheon, the major joints -- ankles, knees, wrists, and even the waist -- are placed in a locked position by flexing the surrounding muscles and ligaments to the utmost degree. In many positions, for example, the hands are held at a 45 degree angle to the arm using the power of the surrounding muscles alone, which is actually more difficult than it sounds -- only by pressing the palm back into that position with the other hand is it easy.
One of the effects of YeokGeun is greater immediate strength. When the joints are locked in this position, for example, the hand becomes elastic and flexible, and therefore much more effective against an opponent.
But the long-term effects of practicing YeokGeun are even more impressive. Typically, when people exercise, they build up the muscles on the outside part of the arm, and ignore the under part of the arm, which remains soft and flaccid. To lock the wrist joints in the Yeok Geun position, however, the muscles on the inside, or under part of the arm must work as hard as the muscles on the outside or upper part. It's a kind of pushing/pulling action whereby the tension of opposing muscles groups -- Yeum and Yang, if you will -- strengthen each other.
Even after a few months of YeokGeun practice, the results are visible; the muscles not only have a leaner appearance, but trainees will notice a roundness to the limbs that comes from a more balanced composition of muscles.
Another purpose of YeokGeun is to generate the free-flow of Gi. The principle here is that the joints are like passages to let Gi easily flow into all areas of the body-- when they aren't properly stretched, the Gi becomes stagnant. Yeok Geon opens up the joints, releasing this Gi into the rest of the body. Trainees might notice pain in certain areas of the body while practicing Yeok Geun in the beginning, usually where an injury or Gi blockage exists. By working these trigger points, however, and releasing the Gi, many injuries can be overcome in time.
YeokGeun also has philosophical implications. The tension between the two opposing muscle groups -- the inner and outer -- embodies the notion of "The Middle Path," the detached or neutral state-of-mind that precedes enlightenment. The tension on the surrounding muscles groups represents the difficulties of life, or turmoil, imposed upon human beings from the outside, while on the inside there is stability and calm -- represented by the locking of the joints.
Without a doubt, the person who practices YeokGeun feels more composed and serene. And only when the human mind is free from all bondage can it realize the cosmic reality.